The present invention relates to cosmetic formulations for topical application containing extracts from Phyllanthus emblica and Centella asiatica and/or Bacopa monnieri, and the use of such formulations for the care of the human skin.
According to the German Lebensmittel- und Bedarfsgegenstandsgesetz (LMBG; food and utility item act), 4th Section, of Aug. 15, 1974, the EC Directive (76/768/EEC) of Sep. 27, 1976, and the German Kosmetik-Verordnung (cosmetics regulation) of Jun. 26, 1985, cosmetic agents are materials or formulations made of substances which are designated for topical application on humans or in their oral cavities for cleaning, care and protection, inter alia. When this definition was established, the idea of consumer protection was given priority.
Especially dermatologists had long been of the opinion that few substances besides water could pass through the barrier layer of the skin, and thus cosmetic agents had no effect, or should not have any. In the meantime, it could be proven that a wide variety of substances can penetrate even intact and healthy skin depending on their molecular weight, molecular structure and size. If special carrier substances, especially emulsifiers, are additionally employed, the number of such substances can be increased many times over.
From cosmetic agents, the consumer also expects specific effects, such as the prevention of premature skin aging, the avoiding or delaying of wrinkle formation, or effective protection against drying of the skin. It is taken for granted that the ingredients employed are free of deleterious actions.
This expectation by the consumer led to the development of so-called xe2x80x9cactive cosmeticsxe2x80x9d, the active ingredients employed being not allowed to have systemic effects, however. In particular, vitamins, minerals and trace elements or animal proteins have been used.
In contrast, in the field of medicinal plants, there are great opportunities of achieving the above mentioned effects without appreciable risks to health, since tolerance thereof is sufficiently proven from the tradition of folk medicine in all important cultures. In particular, the activity of phytopharmaceuticals is based on that fact; in many cases, the active substances from plants have also been used as pure substances. The activity of plant extracts is often lower than that of pure substances. There are also cases, however, where the components of an extract display their activity only as a whole. For chronic diseases, phytopharmaceuticals offer a true alternative to allopathic medicaments, having fewer risks to health.
The 5th edition (1995) of the xe2x80x9cInternational Cosmetic Ingredient Dictionaryxe2x80x9d, edited by the American industrial association CTFA, lists about 300 plants which are added as active ingredients to cosmetic agents in various formulations. A less extensive list, xe2x80x9cEinsatz von pflanzlichen Wirkstoffen und Extrakten in der Hautpflegexe2x80x9d, has been published by D. Bilek, S. B. Singh-Verma and P. Bernhardt (1989), Sxc3x96FW 115, annual volume No. 19, p. 331-338.
EP 0 345 571 B1 relates to a plant extract composition to be used in cosmetics, which especially comprises a tincture prepared from air-dried fruits of the amla plant (emblic; Phyllanthus emblica). The amla fruit (myrobalane) is an Indian medicinal plant; its medical properties have been extensively described in xe2x80x9cEconomic Botanyxe2x80x9d 14/1960, p. 119-128. The tincture from amla fruit mainly contains, in high concentrations, anti-inflammatory tannins, mucic acid, various fruit sugars and a number of free amino acids as well as naturally stabilized vitamin C. As could be proven in extensive application tests with skin and hair care products containing amla tincture, this mixture of substances is highly suitable as a cosmetic agent.
As another medicinal plant of importance to the cosmetics industry, there is to be mentioned Gotu Kola (Brahmi). This designation comprises two species in varying proportions, namely xe2x80x9cCentella asiaticaxe2x80x9d and xe2x80x9cBacopa monnierixe2x80x9d, which are used singly or in combination, depending on the intended use. As the active ingredients of a primary tincture prepared according to HRB I, there are mentioned the alcaloid hydrocotyline, the triterpenic acids (asiatic acid, madecassic acid, madasiatic acid) and the triterpene saponin asiaticoside (Haager""s Handbuch der Drogenkunde). The oral application of an infusion of the medicinal plant is said to have blood-purifying, tonicising and diuretic properties. When applied topically, the extracts and tinctures have antiphlogistic, antibacterial and wound-healing effects which are said to be attributable to an influence on the formation of collagen fibers which occurs in the fibroblasts, i.e., an increased formation of collagen while scarring is retarded.
From xe2x80x9cHager""s Handbuch der Pharmazeutischen Praxisxe2x80x9d, Springer Verlag, 1972, 3rd volume, p. 792-793, it is known that the active substance madecassoid has an anti-inflammatory effect, while asiaticoside, which stimulates mitoses, promotes the healing of premitis and wounds.
In juvenile adults, the renewal of the horny layer is known to take place in a cycle of about three weeks. With increasing age, this rate of proliferation slows down significantly, for example, in 50-year-old and older people. This means that the skin is renewed in a five- or even six-week cycle rather than in a three-week one, and in consequence, it becomes thinner and also drier under the influence of deleterious environmental conditions. The result thereof is the formation of visible wrinkles in the face and body areas.
Thus, it has been the object of the present invention to provide cosmetic formulations for topical application for the care of the human skin, especially for accelerating the natural regeneration of the skin.
In a first embodiment of the invention, the above object is achieved by cosmetic formulations for topical application containing extracts from Phyllanthus emblica and Centella asiatica and/or Bacopa monnieri in addition to per se known adjuvants and expedients.
Surprisingly, it has been found that a combination of the two extracts, when used as active ingredients in skin and body care preparations, has a special cosmetic and care-providing property which results in an acceleration of the natural regeneration of the skin.
In addition to the two extracts mentioned above, in preferred embodiments, the invention provides the use of additional Aloe barbadensis and Hibiscus sabdariffa as emollients having moisturizing or moisture-binding and skin-smoothing properties.
It is considered in the invention that the components of the extracts are available as active substances which quickly act on the surface of the skin. It is particularly important that the components be extracted from the plant parts of the amla plant or the Gotu Kola as gently and completely as possible. The extraction method to be employed essentially depends on the kind of care product to be prepared for which the respective extract is to be used. The components of the amla plant are known to have an astringent and degreasing effect and, in long-term applications, a positive influence and clearly regulating effect on the activity of the sebaceous glands. In face and skin care preparations for greasy or problematic skin, a clear cosmetic effect results at higher concentrations of use. By the application of a corresponding extract, the skin is already tightened and gets a smooth and supple appearance without comedones or other skin impurities. A low dosage is known to result in an excellent tonicising and regenerating effect for dry and mixed skin. Ethanolic extracts, especially ethanolic extracts from fruits, are of particular importance as skin care products for greasy, but also for dry and mixed skin (in low dosage).
xe2x80x9cExtractxe2x80x9d within the meaning of the present invention comprises an extract from the plant parts mentioned as obtained by means of a solvent, optionally under pressure and/or heat. The quality and quantity of the composition of active substances may slightly vary depending on the extractant and extraction method employed.
Of particular importance are extracts from fruits, which may be processed both fresh and in a dried form (amla). Similarly, the extract or the oily extract of Centella asiatica may also be obtained from stalks, flowers, leaves or roots. In a preferred embodiment of the present invention, the formulations contain from 0.1 to 40% by weight of the extracts, especially from 1 to 20% by weight of the extracts, of Phyllanthus emblica and from 1 to 20% by weight of Centella asiatica and/or Bacopa monnieri, the stated weight proportion for the combination of Centella asiatica and Bacopa monnieri referring to the total amount of the two components. If too low a concentration of use is selected, the desired effect will not be achieved. However, if the amounts of extracts are adjusted too high, an economical exploitation is not possible. In addition, considerable galenic problems result in the processing of extracts in the cosmetic formulations.
In addition to the extracts mentioned, the cosmetic formulations optionally contain per se known adjuvants and expedients, such as those known, for example, from Sucker, Fuchs and Speiser, xe2x80x9cPharmazeutische Technologiexe2x80x9d (1978); Schrader, xe2x80x9cGrundlage und Rezepturen der Kosmetikaxe2x80x9d (1989); and Nowak, xe2x80x9cDie kosmetischen Prxc3xa4paratexe2x80x9d, 2nd ed. (1975). There may be mentioned, in particular, vegetable oils, alcohols, emulsifiers, antioxidants, thickeners, UV absorbers, vitamins, minerals, trace elements and/or perfume. For example, a particularly preferred formulation is a fluid which consists of natural active substances and the mentioned plant extracts only. The latter stimulate blood circulation and promote the regeneration of the skin. Natural oils adjust the lipid and moisture balance of the skin and confer elasticity and resilience to it. Vitamins stimulate the cellular activity and protect from environmental influences. Preferably, the fluid is free from colorants and preservatives, quickly penetrates into the skin and does not cause a greasy feel. Further formulations are oil-in-water (o/w) emulsions, for example, moisture fluids or night creams.
Another embodiment of the present invention relates to the use of formulations as defined above for the care of the human skin, especially for accelerating the natural regeneration of the skin.
Since the performance of animal studies for the development of cosmetics is banned under German law, it was not possible to directly prove the epidermic proliferation. Therefore, application tests were performed in several steps under strictly controlled conditions in order to prove a synergistic effect of a combination of extracts from Phyllanthus emblica and Centella asiatica and/or Bacopa monnieri. 
Therefore, from the full drug, i.e., air-dried fruits of Phyllanthus emblica (amla), primary tinctures (extracts) were prepared according to HRB I (extractant: 70% ethanol and 30% demineralized water) and used as active ingredients for cosmetic agents (amla tincture).